Propagation of a Shear Direction Acoustic Wave in Piezoelectric Coupled Cylinders

Abstract

Acoustic wave polarized in the horizontal shear direction (SH wave) have attracted much attention in the topic of smart materials research because of the following reason (123). The particle displacement associated with SH wave has almost zero component normal to the free surface. The absence of the surface normal component avoids fast dispersion of energy into surrounding medium when the subject is immersed in liquids (4). The properties of SH wave traveling in the piezoelectric coupled cylindrical structure are however quite different from that in plate or beam structures (56). In the case of cylindrical geometry, SH wave is polarized along the axis of the cylinder with zero particle displacement component normal to the cylindrical surface. The present paper is concerned with SH wave circulating around a long metallic cylinder covered with a piezoelectric layer. Dispersion relations are obtained, which provides potential application of this structure in the design of nondestructive evaluation of cylindrical structures submerged in water.